(10,21) → ¬Z;AND THUS, WE GET A CONTRADICTION AT 21

10 : - BÁO CÁO TOÁN HỌC FANS AND BUNDLES IN THE GRAPH OF PAIRWISE SUMS AND PRODUCT POTX
Toán BÁO CÁO TOÁN HỌC FANS AND BUNDLES IN THE GRAPH OF PAIRWISE SUMS AND PRODUCT POTX
10: (11,10)→ ¬x; 21: (10,21) → ¬z;and thus, we get a contradiction at 21.[12, z],[19, y] :